[JExtensionPanel]可伸缩的面板

先看代码:

package lfl.swing.comp;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Graphics2D;
import java.awt.Polygon;
import java.awt.RenderingHints;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;

import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;

/**
 * 可以伸缩的面板
 * 
 * @author 李富粮
 * @since 20120806
 * @version 0.0.1
 * */
public class JExtensionPanel extends JPanel implements MouseListener {
	private static final long serialVersionUID = 1L;
	private boolean expand;// 是否展开
	private String title;// 标题
	private JLabel label;// 标题面板
	private Component panel;// 主面板
	private ImageIcon up_icon, down_icon;// 图标

	// ----各种构造函数---------------------------------------
	/**
	 * 可以伸缩的面板,默认展开
	 * 
	 * @author 李富粮
	 * @since 20120806
	 * @version 0.0.1
	 * 
	 * */
	public JExtensionPanel() {
		this("", null, true);
	}

	/**
	 * 可以伸缩的面板,默认展开
	 * 
	 * @author 李富粮
	 * @since 20120806
	 * @version 0.0.1
	 * @param c
	 *            内容面板
	 * */
	public JExtensionPanel(Component c) {
		this("", c, true);
	}

	/**
	 * 可以伸缩的面板,默认展开
	 * 
	 * @author 李富粮
	 * @since 20120806
	 * @version 0.0.1
	 * @param title
	 *            标题
	 * @param c
	 *            内容面板
	 * */
	public JExtensionPanel(String title, Component c) {
		this(title, c, true);
	}

	/**
	 * 可以伸缩的面板
	 * 
	 * @author 李富粮
	 * @since 20120806
	 * @version 0.0.1
	 * @param title
	 *            标题
	 * @param c
	 *            内容面板
	 * @param expand
	 *            默认展开与否
	 * */
	public JExtensionPanel(String title, Component c, boolean expand) {
		this.title = title;
		this.expand = expand;
		this.panel = c;
		init();
	}

	// ----各种方法---------------------------------------
	/**
	 * 返回面板伸缩的状态
	 * */
	public boolean isExpand() {
		return expand;
	}

	/**
	 * 设置面板的伸缩
	 * 
	 * @param true 展开
	 * @param false 收缩
	 * */
	public void setExpand(boolean expand) {
		this.expand = expand;
		if (this.expand) {
			this.label.setIcon(down_icon);
			this.label.setBorder(BorderFactory.createLoweredBevelBorder());
			if (null != this.panel) {
				panel.setVisible(true);
			}
		} else {
			this.label.setIcon(up_icon);
			this.label.setBorder(BorderFactory.createRaisedBevelBorder());
			if (null != this.panel) {
				panel.setVisible(false);
			}
		}
		this.updateUI();
		this.updateUI();
	}

	/**
	 * 返回面板的内容面板
	 * */
	public Component getPanel() {
		return panel;
	}

	/**
	 * 设置内容面板
	 * 
	 * @param panel
	 *            内容面板
	 * */
	public void setPanel(Component panel) {
		if (null != panel) {
			this.remove(this.panel);
			this.panel = panel;
			this.add(this.panel, BorderLayout.CENTER);
			if (this.expand) {
				panel.setVisible(true);
			} else {
				panel.setVisible(false);
			}
		} else {
			this.remove(this.panel);
			this.panel = null;
		}
		this.updateUI();
	}

	/**
	 * 返回面板标题
	 * */
	public String getTitle() {
		return title;
	}

	/**
	 * 设置面板标题
	 * 
	 * @param panel
	 *            面板标题
	 * */
	public void setTitle(String title) {
		this.title = title;
		this.label.setText(title);
		this.updateUI();
	}

	/**
	 * 创建标题指示图标
	 * */
	private void createImages() {
		int w = this.getPreferredSize().width, h = this.getPreferredSize().height;
		BufferedImage open = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB), close = new BufferedImage(
				w, h, BufferedImage.TYPE_INT_RGB);
		// 展开的图标
		Graphics2D g2 = open.createGraphics();
		g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
				RenderingHints.VALUE_ANTIALIAS_ON);
		g2.setPaint(this.getBackground());
		g2.fillRect(0, 0, w, h);
		int[] x = { 0, w / 2, w };
		int[] y = { h / 4, 3 * h / 4, h / 4 };
		Polygon p = new Polygon(x, y, 3);
		g2.setPaint(Color.BLACK);
		g2.fill(p);
		g2.setPaint(Color.BLACK);
		g2.draw(p);
		g2.dispose();
		down_icon = new ImageIcon(open);
		// 收缩的的图标
		g2 = close.createGraphics();
		g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
				RenderingHints.VALUE_ANTIALIAS_ON);
		g2.setPaint(getBackground());
		g2.fillRect(0, 0, w, h);
		x = new int[] { w / 4, 3 * w / 4, w / 4 };
		y = new int[] { 0, h / 2, h };
		p = new Polygon(x, y, 3);
		g2.setPaint(Color.GRAY);
		g2.fill(p);
		g2.setPaint(Color.GRAY);
		g2.draw(p);
		g2.dispose();
		up_icon = new ImageIcon(close);
	}

	/**
	 * 初始化工作
	 * */
	private void init() {
		this.createImages();// 获得图标
		this.setLayout(new BorderLayout());
		if (this.expand) {
			this.label = new JLabel(this.title, this.down_icon,
					SwingConstants.LEADING);
			this.label.setBorder(BorderFactory.createLoweredBevelBorder());
			if (null != this.panel) {
				this.add(this.panel, BorderLayout.CENTER);
			}
		} else {
			this.label = new JLabel(this.title, this.up_icon,
					SwingConstants.LEADING);
			this.label.setBorder(BorderFactory.createRaisedBevelBorder());
			if (null != this.panel) {
				this.add(this.panel, BorderLayout.CENTER);
				this.panel.setVisible(false);
			}
		}
		this.add(this.label, BorderLayout.NORTH);

		this.label.addMouseListener(this);
	}

	// ----接口方法的实现---------------------------------------

	@Override
	public void mouseClicked(MouseEvent e) {
		if (e.getSource() == label) {
			expand = !expand;
			if (this.expand) {
				this.label.setIcon(down_icon);
				this.label.setBorder(BorderFactory.createLoweredBevelBorder());
				if (null != this.panel) {
					panel.setVisible(true);
				}
			} else {
				this.label.setIcon(up_icon);
				this.label.setBorder(BorderFactory.createRaisedBevelBorder());
				if (null != this.panel) {
					panel.setVisible(false);
				}
			}
			this.updateUI();
		}
	}

	@Override
	public void mouseEntered(MouseEvent e) {
	}

	@Override
	public void mouseExited(MouseEvent e) {
	}

	@Override
	public void mousePressed(MouseEvent e) {
	}

	@Override
	public void mouseReleased(MouseEvent e) {
	}

	public static void main(String[] args) {
		JFrame f = new JFrame();
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		Container c = f.getContentPane();
		c.setLayout(new BorderLayout());

		c
				.add(new JExtensionPanel("test1", new JButton("test1"),false),
						BorderLayout.NORTH);
		c
		.add(new JExtensionPanel("test2", new JButton("test2"),false),
				BorderLayout.CENTER);
		f.setSize(360, 500);
		f.setLocation(200, 100);
		f.setVisible(true);
	}
}

看看效果吧:








自己写的一个软件：